The Australian Transport Safety Bureau (ATSB) is Australia's national transport safety investigator. The ATSB's function is to improve safety and public confidence in the aviation, marine and rail modes of transport. The ATSB is Australia's prime agency for the independent investigation of civil aviation, rail and maritime accidents, incidents and safety deficiencies.

On 5 September 2005, at 1004 local time, a Boeing Co 737-200 aircraft, registration PK-RIM, crashed into an urban residential area after takeoff from runway 23 of the Medan-Pollonia Airport, Medan, Sumatra, Indonesia. There were 5 crew and 112 passengers on board. The crew and 96 passengers, along with 44 persons on the ground, were fatally injured; 16 passengers survived.

The occurrence is being investigated by the National Transportation Safety Committee (NTSC) of the Ministry of Transportation, Republic of Indonesia. On 10 February 2006, the NTSC requested specialist assistance from the ATSB with the examination of cockpit voice recorder (CVR) information. In accordance with clause 5.231 of Annex 13 to the Convention on International Civil Aviation, the ATSB appointed an Accredited Representative to assist the Indonesian authority.

PK-RIM was fitted with both a flight data recorder and a CVR. Both units were recovered from the aircraft wreckage.

The ATSB initiated an investigation under the Transport Safety Investigation (TSI) Act 2003.Section 48 of the TSI Act,defines CVR information as an on board recordingand is afforded appropriate protection.

A detailed examination of the CVR information was made under the supervision of NTSC investigators during the week beginning 17 July 2006.

The NTSC is the independent Indonesian government entity responsible for the investigation of accidents and incidents involving Indonesian registered and operated aircraft. The ATSB Accredited Representative's role in the investigation has been to provide the NTSC investigators with assistance in examining CVR information. A report regarding the examination of the CVR information was prepared and forwarded to the NTSC Investigator in Charge for his consideration.

The NTSC is responsible for the final investigation report regarding this occurrence.

Any State which on request provides information, facilities or experts to the State conducting the investigation shall be entitled to appoint an accredited representative to participate in the investigation.